Annular relay melt electrospinning device and regulation method

Abstract

The application belongs to the technical field of electrospinning, and discloses a kind of annular relay melt electrospinning device and regulation method. By adjusting the gap size between the upper assembly and the lower assembly of the spinning nozzle through the screw on the spinning nozzle, the initial melt layer thickness is adjusted, and the melt supply is adjusted. The fiber output and fiber diameter parameters are regulated by cooperating with the applied voltage. The screw-in depth adjustment range is 0.5-5mm. The application can realize spinning in the same direction of the upper and lower two directions of the same melt thin layer, and the two directions of spinning share a melt thin layer. The application can balance the contradictory relationship between the melt thin layer and the fiber diameter, and realize further reduction of the fiber diameter and improvement of the fiber output efficiency under the existing melt extrusion technology and melt thin layer distribution conditions.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrostatic spinning, and in particular relates to a ring-shaped relay melt electrostatic spinning device and a control method. Background Art

[0002] Electrospinning is a process for producing ultrafine polymer fibers by forming a jet from a charged polymer solution or melt in an electrostatic field. Under an applied electric field, charges accumulate on the surface of polymer droplets, inducing an electric force opposite to the surface tension. As the electric force gradually increases, the polymer droplets are elongated from a spherical shape to a cone, forming the so-called "Taylor cone." When the electric field intensity continues to increase to a critical value, the electric force exerted on the polymer droplets overcomes the surface tension to form a jet. As the jet falls, as the solvent evaporates or the melt cools and solidifies, fibers are formed and randomly scattered on a collection device to form a nonwoven fabric.

[0003] Nonwoven fabrics produced by electrospinning have the advantages of high porosity, large specific surface area, high fiber fineness and uniformity, and a large aspect ratio, and have broad application potential. Depending on the spinning medium, electrospinning can be divided into two types: solution electrospinning and melt electrospinning. Solution electrospinning does not require heating and temperature control devices, and the equipment is relatively simple. However, the solvent content is large, the fiber production efficiency is low, and solvent evaporation can easily cause environmental problems. Melt electrospinning converts all raw materials into fibers, which is highly efficient and is a promising technology for the preparation of ultrafine fibers.

[0004] Due to the high melt viscosity, the diameter of fibers prepared by electrospinning is generally thicker. Therefore, how to further improve the fiber output efficiency while effectively reducing the fiber diameter is one of the key issues in realizing the industrialization of melt electrospinning.

[0005] Through the above analysis, the problems and defects of the existing technology are as follows: (1) The output efficiency of the existing melt electrospinning method in batch preparation of fibers is low and the fiber diameter is relatively thick; (2) The existing technology spins one layer of melt thin layer at a time. If you want to reduce the fiber diameter, you must reduce the thickness of the melt thin layer. However, due to the high viscosity of the melt and the difficulty of achieving micro-extrusion through high-precision equipment, it is very difficult to reduce the thickness of the melt thin layer and there is a limit. Therefore, there is a technical bottleneck in reducing the diameter of melt electrospun fibers by reducing the thickness of the melt thin layer. Summary of the Invention

[0006] In order to overcome the problems existing in the related art, the embodiments disclosed in the present invention provide a ring-shaped relay melt electrospinning device and a control method.

[0007] The technical solution is as follows: A control method for a ring-shaped relay melt electrospinning device, comprising:

[0008] By adjusting the screw in the spinning nozzle, the gap size between the upper component and the lower component of the nozzle is adjusted, the initial melt layer thickness is adjusted and then the melt supply amount is adjusted, and the fiber output and fiber diameter and other parameters are controlled in conjunction with the applied voltage.

[0009] In one embodiment, the screw-in depth of the screw is adjusted in a range of 0.5-5 mm.

[0010] In one embodiment, the applied voltage includes: a high-voltage electrostatic voltage of 5-30 kV output by high-voltage electrostatic generator 2, a voltage of 50-100 kV output by high-voltage electrostatic generator 1 and high-voltage electrostatic generator 3 with the same output polarity as high-voltage electrostatic generator 2, or a voltage of 5-50 kV output with the opposite polarity to high-voltage electrostatic generator 2.

[0011] In one embodiment, the control method of the annular relay melt electrospinning device further comprises:

[0012] S1: The annular relay body is directly charged, so that the protruding annular edge of the nozzle lower assembly of the spinning nozzle is induced to be charged. The initial melt layer uniformly distributed circumferentially at the annular edge is polarized and charged and then differentiated into multiple stable and uniform jets. The jets are attracted by the electric field force toward the inner surface of the annular relay body, so that the melt is evenly spread on the inner surface of the annular relay body to form a thin melt layer;

[0013] S2, by forming aggregated charges on the upper and lower annular edge surfaces of the annular relay body, uniform and stable spinning is achieved on the upper and lower surfaces of the annular relay body.

[0014] Another object of the present invention is to provide a ring-shaped relay melt electrospinning device, the device being provided with an upper electrode plate, the upper electrode plate being sleeved outside a spinning nozzle and coaxially arranged with the spinning nozzle, the upper electrode plate being placed on the upper part of a ring-shaped relay body, the ring-shaped relay body being coaxially arranged with the spinning nozzle and sleeved outside the spinning nozzle; the left side of the ring-shaped relay body being connected to an air inlet pipe, and the right side being connected to an air outlet pipe, the air inlet pipe and the air outlet pipe simultaneously serving as supports for the ring-shaped relay body to keep the ring-shaped relay body in a suspended position;

[0015] The lower electrode plate is coaxially arranged with the spinning nozzle and placed at the lower part of the spinning nozzle, the upper electrode plate is connected to the first high-voltage electrostatic generator, the annular relay is connected to the second high-voltage electrostatic generator, the lower electrode plate is connected to the third high-voltage electrostatic generator, and the spinning nozzle is grounded.

[0016] In one embodiment, the spinning nozzle consists of an upper nozzle assembly, a lower nozzle assembly and screws. Four screws evenly distributed along the circumference connect the upper nozzle assembly and the lower nozzle assembly together and leave a certain distance between the upper nozzle assembly and the lower nozzle assembly. The size of this gap is adjusted by adjusting the screw-in depth.

[0017] In one embodiment, the nozzle upper component is a cylindrical rotating body structure with a melt channel in the center, a feeding hole at the top, and an expanded hemispherical structure at the bottom. The nozzle lower component is a hemispherical structure, and the upper surface of the nozzle lower component is 1-10 mm larger in diameter than the lower surface of the nozzle upper component. The spinning nozzle is made of a conductive metal material.

[0018] In one embodiment, a polymer melt enters the upper component of the nozzle through a feeding hole, and the melt enters the gap between the upper component of the nozzle and the lower component of the nozzle through a central channel of the upper component of the nozzle to form a uniform initial melt layer. The second high-voltage electrostatic generator is turned on and the voltage is adjusted. The annular relay body is charged, and the edge of the upper surface of the lower component of the nozzle protrudes to form an annular tip, and close to the inner surface of the annular relay body, a dense induced charge is formed on the annular tip, and the initial melt layer distributed on the annular tip is polarized to form a polarized charge. The polarized charge has an opposite polarity to the charge on the annular relay body, and opposite charges attract. After the attraction of the polarized charge exceeds the surface tension of the melt, the polymer melt self-organizes to form a uniform multi-melt jet toward the inner surface of the annular relay body, and is evenly distributed on the inner surface of the annular relay body to form a thin melt layer;

[0019] The high-temperature airflow enters from the air flow inlet and enters the internal space of the annular relay body through the air inlet pipe. The high-temperature airflow surrounds the annular relay body and is discharged from the air flow outlet of the air outlet pipe. The high-voltage electrostatic generator one and the high-voltage electrostatic generator three are turned on, and the output polarity is the same as that of the high-voltage electrostatic generator two, or the output polarity is opposite to that of the high-voltage electrostatic generator two. A concentrated induced charge is formed at the annular tips on the upper and lower surfaces of the annular relay body, which attracts the initial melt layer on the inner surface of the annular relay body to flow toward the annular tips on the upper and lower surfaces respectively and excite to form stable and uniform multi-melt jets that are sprayed on the upper and lower electrode plate surfaces respectively. The melt jets cool during the spraying process to form fibers and are attracted by the upper and lower electrode plates.

[0020] In one embodiment, the annular relay body is an annular structure as a whole, and the cross-section is a circular tubular. The left side of the annular relay body is connected to the air inlet pipe, and the right side is connected to the air outlet pipe. The air inlet pipe and the air outlet pipe simultaneously serve as the support of the annular relay body to keep the annular relay body in a suspended position. The other end of the air inlet pipe is the air flow inlet, and the other end of the air outlet pipe is the air flow outlet.

[0021] In one embodiment, the lower electrode plate is a circular plate structure, which is coaxially arranged with the spinning nozzle and placed at the bottom of the spinning nozzle. The electrode plate is connected to the first high-voltage electrostatic generator, the annular relay is connected to the second high-voltage electrostatic generator, the lower electrode plate is connected to the third high-voltage electrostatic generator, and the spinning nozzle is grounded.

[0022] Combining all the above technical solutions, the advantages and positive effects of the present invention are as follows: The purpose of the present invention is to solve the problems of low output efficiency and coarse fiber diameter in the batch preparation of fibers by melt electrospinning, and propose a ring-shaped relay melt electrospinning device and method, in which the melt is sprayed onto the surface of the ring-shaped relay body by an electrostatic jet method, so that the melt is evenly spread on the surface of the ring-shaped relay body to form a thin layer of melt, and then the accumulated charges are formed on the upper and lower annular edge surfaces of the ring-shaped relay body to achieve uniform and stable spinning on the upper and lower surfaces of the ring-shaped relay body.

[0023] The present invention can realize simultaneous spinning in the upper and lower directions of the same layer of melt thin layer, and the two directions of spinning share a common melt thin layer. The previous technology all spins one melt thin layer at a time. If you want to reduce the fiber diameter, you must reduce the thickness of the melt thin layer. However, due to the high viscosity characteristics of the melt and the difficulty of achieving micro-extrusion through high-precision equipment, it is very difficult to reduce the thickness of the melt thin layer and there is a limit value. Therefore, there is a technical bottleneck in reducing the diameter of the melt electrospun fiber by reducing the thickness of the melt thin layer. The present invention can balance the contradictory relationship between the melt thin layer and the fiber diameter, and achieve further reduction of the fiber diameter and improvement of the fiber output efficiency under the existing melt extrusion technology and melt thin layer distribution conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure;

[0025] Figure 1 Schematic diagram of a ring-shaped relay melt electrospinning device provided by an embodiment of the present invention;

[0026] Figure 2 Schematic diagram of a spinning nozzle provided by an embodiment of the present invention;

[0027] Figure 3 This is a flow chart of a control method for a ring-shaped relay melt electrospinning device provided by an embodiment of the present invention;

[0028] In the figure: 1-spinning nozzle, 2-upper electrode plate, 3-annular relay body, 4-inlet pipe, 5-outlet pipe, 6-lower electrode plate, 7-melt jet, 8-fiber, 9-high-voltage electrostatic generator 1, 10-high-voltage electrostatic generator 2, 11-high-voltage electrostatic generator 3, 101-nozzle upper assembly, 102-screw, 103-nozzle lower assembly, 104-feeding hole, 105-initial melt layer, 401-air flow inlet, 501-air flow outlet. DETAILED DESCRIPTION

[0029] To make the above-mentioned objects, features, and advantages of the present invention more readily apparent, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. The following description sets forth numerous specific details to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0030] Example 1, as Figure 1 、 Figure 2 As shown, the annular relay melt electrospinning device provided by the embodiment of the present invention includes: a spinning nozzle 1, an upper electrode plate 2, a ring relay body 3, an air inlet pipe 4, an air outlet pipe 5, a lower electrode plate 6, a melt jet 7, a fiber 8, a high-voltage electrostatic generator 1 9, a high-voltage electrostatic generator 2 10, a high-voltage electrostatic generator 3 11, an upper nozzle assembly 101, a screw 102, a lower nozzle assembly 103, a feeding hole 104, an initial melt layer 105, an air flow inlet 401, and an air flow outlet 501.

[0031] Among them, the upper electrode plate 2 is an annular plate-shaped structural part with a circular hole in the center. The upper electrode plate 2 is made of a conductive metal material such as copper. The upper electrode plate 2 is sleeved on the outside of the spinning nozzle 1 and arranged coaxially with the spinning nozzle 1. The upper electrode plate 2 is placed on the upper part of the annular relay body 3, and the height difference with the center section of the annular relay body 3 is 50-200mm; the annular relay body 3 is coaxially arranged with the spinning nozzle 1 and sleeved on the outside of the spinning nozzle 1. The center section of the annular relay body 3 is placed on the same as the lower surface of the initial melt layer 105. In plan view, the annular relay body 3 is an annular structure as a whole, and its cross section is a circular tubular. The left side of the annular relay body 3 is connected to the air inlet pipe 4, and the right side is connected to the air outlet pipe 5. The air inlet pipe 4 and the air outlet pipe 5 also serve as brackets for the annular relay body 3 to keep the annular relay body in a suspended position. The annular relay body 3 is made of a conductive metal material such as copper, and the air inlet pipe 4 and the air outlet pipe 5 are made of a heat-resistant insulating material such as polytetrafluoroethylene. The other end of the air inlet pipe 4 is an air flow inlet 401, and the other end of the air outlet pipe 5 is an air flow outlet 501.

[0032] The lower electrode plate 6 is a circular plate structure, made of metal conductive material such as copper, coaxially arranged with the spinning nozzle 1 and placed at the lower part of the spinning nozzle 1, with a height difference of 50-200mm from the annular relay body 3; the upper electrode plate 2 is connected with the high-voltage static generator one 9, the annular relay body 3 is connected with the high-voltage static generator two 10, the lower electrode plate 6 is connected with the high-voltage static generator three 11, and the spinning nozzle 1 is grounded. The spinning nozzle 1 is composed of a nozzle upper assembly 101, a nozzle lower assembly 103 and a screw 102, four screws 102 evenly distributed in the circumferential direction connect the nozzle upper assembly 101 and the nozzle lower assembly 103 together and leave a certain distance gap between the nozzle upper assembly 101 and the nozzle lower assembly 103, the size of the gap can be adjusted by adjusting the screwing depth of the screw 102, the adjustment range is 0.5-5mm, the gap adjustment size is related to the melt viscosity and the required fiber 8 diameter, when the required fiber 8 has the same diameter, the melt of high molecular material with high viscosity needs a larger gap opening, because the melt with high viscosity has poor flowability, in order to facilitate the melt to flow out, a larger opening is needed, the gap adjustment range is set to adapt to the melt viscosity of most high molecular materials; when the melt viscosity is fixed and the fiber 8 diameter needs to be changed, the size of the gap can be changed to achieve the change, reducing the gap will reduce the melt supply rate, and the thin layer thickness of the melt will be smaller, and the fiber 8 will be thinner, and vice versa, the fiber 8 will be thicker.

[0033] In the embodiment of the application, the nozzle upper assembly 101 is a cylindrical rotary body structure, the center has a melt channel, the top end is a feeding hole 104, and the bottom end is an enlarged hemispherical structure, the nozzle lower assembly 103 is a hemispherical structure, the upper surface of the nozzle lower assembly 103 is 1-10mm larger in diameter than the lower surface of the nozzle upper assembly 101, and the spinning nozzle 1 is made of metal conductive material such as copper.

[0034] The polymer melt enters the nozzle assembly 101 through the feeding hole 104, and the melt enters the gap between the nozzle assembly 101 and the nozzle lower assembly 103 through the central channel of the nozzle assembly 101 to form a uniform initial melt layer 105. Turn on the high-voltage electrostatic generator 102, adjust the voltage to 5-30kV, and the annular relay body 3 is directly charged. Since the upper surface of the nozzle lower assembly 103 is larger in diameter than the lower surface of the nozzle upper assembly 101, the edge of the upper surface of the nozzle lower assembly 103 protrudes to form an annular tip, and is close to the inner surface of the annular relay body 3. A dense induced charge is formed on the annular tip, and the initial melt layer 105 distributed on the annular tip is polarized to form a polarized charge. The polarized charge has an opposite polarity to the charge on the annular relay body 3, and opposite charges attract. After the attraction of the polarized charge exceeds the surface tension of the melt, the polymer melt self-organizes to form a uniform multi-melt jet 7 toward the inner surface of the annular relay body 3, and is evenly distributed on the inner surface of the annular relay body 3 to form a thin layer of melt; the high-temperature airflow from The air flow enters through the air inlet 401 and enters the internal space of the annular relay body 3 through the air inlet pipe 4. The high-temperature air flow surrounds the annular relay body 3 and is discharged from the air flow outlet 501 of the air outlet pipe 5. The high-temperature air flow is used to maintain the temperature of the annular relay body 3 so that the initial melt layer 105 on its upper part maintains a good flow state. Then the high-voltage electrostatic generator 1 9 and the high-voltage electrostatic generator 3 11 are turned on, and the output polarity is the same as that of the high-voltage electrostatic generator 2 10, and the output voltage is adjusted to 50-100kV; the output polarity can also be opposite to that of the high-voltage electrostatic generator 2 10, and the output voltage is adjusted to 5-50kV. At this time, concentrated induced charges are formed at the annular tips on the upper and lower surfaces of the annular relay body 3, which in turn attracts the initial melt layer 105 on the inner surface of the annular relay body 3 to flow toward the annular tips on the upper and lower surfaces respectively and excite to form stable and uniform multi-solvent jets 7, which are respectively sprayed on the surfaces of the upper and lower electrode plates 6. The melt jets 7 cool during the spraying process to form fibers 8 and are attracted by the upper and lower electrode plates 6.

[0035] The gap between the upper nozzle assembly 101 and the lower nozzle assembly 103 is adjusted by screw 102, thereby adjusting the thickness of the initial melt layer 105 to achieve the purpose of adjusting the melt supply amount, and finally achieving the regulation of product parameters such as the output of fiber 8 and the diameter of fiber 8 in conjunction with the applied voltage.

[0036] In Example 2, a polypropylene (PP) melt is introduced into the nozzle assembly 101 from the feeding hole 104, and the melt forms an initial melt layer 105 in the gap between the nozzle assembly 101 and the nozzle lower assembly 103. The thickness of the initial melt layer 105 is adjusted to 2 mm, and a high-temperature airflow of 260°C is introduced into the airflow inlet 401. The high-temperature airflow is used to maintain the surface temperature of the annular relay body 3 at about 250°C. The high-voltage electrostatic generator 10 is turned on and its voltage is adjusted to 15 kV. At this time, about 30 uniform and stable jets are formed from the annular edge of the initial melt layer 105 and sprayed onto the inner surface of the annular relay body 3. A polypropylene melt film is formed on the surface, and at the same time, high-voltage electrostatic generator 1 9 and high-voltage electrostatic generator 3 11 are turned on, and the voltage of high-voltage electrostatic generator 1 9 is adjusted to 45kV, and the voltage of high-voltage electrostatic generator 3 11 is adjusted to 70kV. At this time, about 120 uniform and stable fibers 8 are formed on the annular tips of the upper and lower surfaces of the annular relay body 3, and are respectively sprayed onto the surfaces of the upper and lower electrode plates 6 for collection. The diameter range of the fibers 8 is 600nm-1μm. This technology can achieve the improvement of the output efficiency of the fibers 8 while reducing the average diameter of the fibers 8 and making the diameter of the fibers 8 adjustable, and can realize the batch preparation of melt electrospun ultrafine fibers 8.

[0037] Example 3, an embodiment of the present invention provides a control method for a ring-shaped relay melt electrospinning device, comprising:

[0038] By adjusting the screw 102 in the spinning nozzle 1, the gap size between the nozzle upper component 101 and the nozzle lower component 103 is adjusted, the thickness of the initial melt layer 105 is adjusted and then the melt supply amount is adjusted, and the fiber 8 output and fiber 8 diameter product parameters are regulated in conjunction with the applied voltage.

[0039] The screwing depth of the screw 102 can be adjusted within a range of 0.5-5 mm.

[0040] The applied voltage includes: the high-voltage electrostatic voltage of 5-30kV output by the high-voltage electrostatic generator 2 10, the voltage of 50-100kV output by the high-voltage electrostatic generator 1 9 and the high-voltage electrostatic generator 3 11 with the same output polarity as the high-voltage electrostatic generator 2 10, or the voltage of 5-50kV output with the opposite polarity to the high-voltage electrostatic generator 2 10.

[0041] like Figure 3 As shown, the control method of the annular relay melt electrospinning device provided by the embodiment of the present invention includes:

[0042] S1, the annular relay body 3 is directly electrified, the spinneret lower assembly 103 of the spinning nozzle 1 is protruded from the annular edge, the initial melt layer 105 uniformly distributed at the annular edge is polarized and electrified, and a plurality of stable and uniform jets 7 are formed, the jets 7 are attracted to the inner side surface of the annular relay body 3 under the action of an electric field, and the melt is uniformly laid on the inner side surface of the annular relay body 3 to form a melt thin layer;

[0043] S2, by forming accumulated charges on the upper and lower annular edge surfaces of the annular relay body 3, uniform and stable spinning of the upper and lower surfaces of the annular relay body 3 is realized.

[0044] In the above embodiments, the description of each embodiment has its own emphasis, and the parts not described or recorded in a certain embodiment can be referred to the related description of other embodiments.

[0045] Experiments show that the technical scheme described in the application can be applied to batch production of micro-nano fibers, and is used for efficiently and stably producing micro-nano fibers of polymer materials. Micro-nano fiber materials have been widely used in many fields such as automobiles, medical treatment and aviation, and have a broad market prospect in the future. There is still much potential to be developed in nanofiber technology, and more application fields will appear in the future. The application can realize twice electrospinning of a melt thin layer at the same time, thereby increasing the fiber output efficiency and reducing the fiber diameter.

[0046] The application solves the technical problem that the fiber production efficiency and diameter cannot be considered in the electrospinning industry. The application overcomes the technical prejudice that electrospinning technology can only spin in one direction at a time.

[0047] The above is only a preferred specific embodiment of the application, but the protection scope of the application is not limited thereto, any modification, equivalent replacement and improvement made by those skilled in the art within the technical range disclosed in the application and in the spirit and principle of the application should be covered in the protection scope of the application.

Claims

1. A control method for a ring-shaped relay melt electrospinning device, characterized in that: The method includes: By adjusting the screw (102) in the spinning nozzle (1), the gap between the nozzle upper component (101) and the nozzle lower component (103) is adjusted, the thickness of the initial melt layer (105) is adjusted, and the melt supply is adjusted, and the output of the fiber (8) and the diameter parameters of the fiber (8) are regulated in conjunction with the applied voltage; The control method of the annular relay melt electrospinning device further includes: S1, the annular relay body (3) is directly charged, so that the protruding annular edge of the nozzle lower component (103) of the spinning nozzle (1) is induced to be charged, and the initial melt layer (105) uniformly distributed circumferentially at the annular edge is polarized and charged and then differentiated to form stable and uniform multiple jets (7), and the jets (7) are attracted by the electric field force toward the inner surface of the annular relay body (3), so that the melt is evenly spread on the inner surface of the annular relay body (3) to form a thin melt layer; S2, by forming aggregated charges on the upper and lower annular edge surfaces of the annular relay body (3), thereby achieving uniform and stable spinning on the upper and lower surfaces of the annular relay body (3).

2. The control method of the annular relay melt electrospinning device according to claim 1, characterized in that: The screwing depth of the screw (102) can be adjusted within a range of 0.5-5 mm.

3. The control method of the annular relay melt electrospinning device according to claim 1, characterized in that: The applied voltage includes: a high-voltage electrostatic voltage of 5-30 kV output by the high-voltage electrostatic generator 2 (10), a voltage of 50-100 kV output by the high-voltage electrostatic generator 1 (9) and the high-voltage electrostatic generator 3 (11) with the same output polarity as the high-voltage electrostatic generator 2 (10), or a voltage of 5-50 kV output with the opposite polarity to the high-voltage electrostatic generator 2 (10).

4. A ring-shaped relay melt electrospinning device, characterized in that: The control method of the annular relay melt electrospinning device according to any one of claims 1 to 3 is implemented, wherein the device is provided with an upper electrode plate (2), the upper electrode plate (2) is sleeved on the outside of the spinning nozzle (1) and is coaxially arranged with the spinning nozzle (1), the upper electrode plate (2) is placed on the upper part of the annular relay body (3), the annular relay body (3) is coaxially arranged with the spinning nozzle (1) and sleeved on the outside of the spinning nozzle (1); the left side of the annular relay body (3) is connected to the air inlet pipe (4), and the right side is connected to the air outlet pipe (5), and the air inlet pipe (4) and the air outlet pipe (5) simultaneously serve as supports for the annular relay body (3) to keep the annular relay body (3) in a suspended position; The lower electrode plate (6) is coaxially arranged with the spinning nozzle (1) and placed at the lower part of the spinning nozzle (1), the upper electrode plate (2) is connected to the high-voltage electrostatic generator 1 (9), the annular relay body (3) is connected to the high-voltage electrostatic generator 2 (10), the lower electrode plate (6) is connected to the high-voltage electrostatic generator 3 (11), and the spinning nozzle (1) is grounded.

5. The annular relay melt electrospinning device according to claim 4, characterized in that: The spinning nozzle (1) is composed of an upper nozzle assembly (101), a lower nozzle assembly (103) and screws (102). Four screws evenly distributed along the circumference connect the upper nozzle assembly (101) and the lower nozzle assembly (103) together, and leave a certain distance between the upper nozzle assembly (101) and the lower nozzle assembly (103). The size of the gap is adjusted by adjusting the screwing depth of the screw (102).

6. The annular relay melt electrospinning device according to claim 5, characterized in that: The upper nozzle assembly (101) is a cylindrical rotating body structure with a melt channel in the center, a feeding hole (104) at the top, and an expanded hemispherical structure at the bottom. The lower nozzle assembly (103) is a hemispherical structure. The upper surface of the lower nozzle assembly (103) is 1-10 mm larger in diameter than the lower surface of the nozzle assembly (101). The spinning nozzle (1) is made of a metal conductive material.

7. The annular relay melt electrospinning device according to claim 5, characterized in that: The polymer melt enters the nozzle upper component (101) through the feeding hole (104), and the melt enters the gap between the nozzle upper component (101) and the nozzle lower component (103) through the central channel of the nozzle upper component (101) to form a uniform initial melt layer (105). The high-voltage electrostatic generator (10) is turned on and the voltage is adjusted. The annular relay (3) is charged, and the edge of the upper surface of the nozzle lower component (103) protrudes to form an annular tip, and is close to the inner surface of the annular relay (3). The annular tip forms a dense induced charge, and the initial melt layer (105) distributed on the annular tip is polarized to form a polarized charge. The polarized charge has an opposite polarity to the charge on the annular relay (3). Opposites attract. After the attraction force on the polarized charge exceeds the surface tension of the melt, the polymer melt self-organizes to form a uniform multi-melt jet (7) toward the inner surface of the annular relay (3) and is evenly distributed on the inner surface of the annular relay (3) to form a thin melt layer. The high-temperature airflow enters from the airflow inlet (401), enters the inner space of the annular relay body (3) through the air inlet pipe (4), and is discharged from the airflow outlet (501) of the air outlet pipe (5) after circling along the annular relay body (3). The high-voltage electrostatic generator 1 (9) and the high-voltage electrostatic generator 3 (11) are turned on, and the output polarity is the same as that of the high-voltage electrostatic generator 2 (10), or the output polarity is opposite to that of the high-voltage electrostatic generator 2 (10). A concentrated induced charge is formed at the annular tips of the upper and lower surfaces of the annular relay body (3), which attracts the initial melt layer (105) on the inner surface of the annular relay body (3) to flow toward the annular tips of the upper and lower surfaces respectively and stimulate to form a stable and uniform multi-melt jet (7) which is sprayed onto the surface of the upper and lower electrode plates (6) respectively. The melt jet (7) cools during the spraying process to form a fiber (8) and is attracted by the upper electrode plate (2) and the lower electrode plate (6).

8. The annular relay melt electrospinning device according to claim 5, characterized in that: The annular relay body (3) is an annular structure as a whole, and its cross section is a circular tube. The left side of the annular relay body (3) is connected to the air inlet pipe (4), and the right side is connected to the air outlet pipe (5). The air inlet pipe (4) and the air outlet pipe (5) simultaneously serve as supports for the annular relay body (3) so that the annular relay body (3) is kept in a suspended position. The other end of the air inlet pipe (4) is an air flow inlet (401), and the other end of the air outlet pipe (5) is an air flow outlet (501).

9. The annular relay melt electrospinning device according to claim 5, characterized in that: The lower electrode plate (6) is a circular plate-shaped structure. The lower electrode plate (6) is coaxially arranged with the spinning nozzle (1) and placed at the lower part of the spinning nozzle (1). The electrode plate (2) is connected to the high-voltage electrostatic generator (9). The annular relay (3) is connected to the high-voltage electrostatic generator (10). The lower electrode plate (6) is connected to the high-voltage electrostatic generator (11). The spinning nozzle (1) is grounded.

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